It's hard to say for sure. My best guess is that some of the data in memory somehow became corrupted -- the hope being that it is a one time thing and will work fine from now on. If it happens again soon, I'd suggest doing an actual factory reset and restoring the iPad. Of course, it is possible that it is a hardware issue and, if it keeps happening then I'd suggest getting the tablet checked at an Apple store.

It's hard to say for sure. My best guess is that some of the data in memory somehow became corrupted -- the hope being that it is a one time thing and will work fine from now on. If it happens again soon, I'd suggest doing an actual factory reset and restoring the iPad. Of course, it is possible that it is a hardware issue and, if it keeps happening then I'd suggest getting the tablet checked at an Apple store.